Apparatus and Method for Securing Underdrain Filter Block

ABSTRACT

An underdrain filter block includes a top wall, a pair of side walls extending from the top wall, a bottom wall extending between the pair of side walls, first and second ribs, and a wall segment extending between the first rib and the second rib to define a grout chamber configured to receive grout during installation of the underdrain filter block.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 12/983,465filed on Jan. 3, 2011, which claims the benefit of U.S. ProvisionalApplication No. 61/295,891, filed Jan. 18, 2010. The disclosure of eachof these documents is hereby incorporated in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an underdrain filter block and, moreparticularly, to a filter block used in draining and backwashing afiltering media in a filter bed and a method of securing the filterblock to the filter floor.

2. Description of Related Art

Underdrain filter blocks provide a filter bottom by assembling a numberof filter blocks together to provide an upper surface for supporting afilter media. The filter bottom upper surface is provided with openingsto allow the flow of filtered liquid from the filter media to pass intothe filter bottom where conduits carry the filtered liquid from thefilter. The conduits also serve to provide backwashing fluids, such asgas or liquid, or both, to the filter media for cleaning. U.S. Pat. No.5,108,627 to Berkebile et al. discloses a filter underdrain block and ishereby incorporated by reference in its entirety.

Generally, conventional underdrain filter blocks are susceptible touplift failure due to an internal pressure caused by headloss throughthe underdrain. The headloss, or internal pressure of the conventionalunderdrain blocks, tends to force the block off the filter floor as abottom section of the underdrain block deflects or deforms from internalpressure.

U.S. Pat. No. 3,956,134 to Sturgill discloses, as shown in FIGS. 5, 6,and 13, an underdrain unit with a bottom wall that extends outwardlybeyond sidewalls to define a flange. Perforations in the bottom wallhelp to secure the underdrain to the floor of the filter basin byengaging with grouting material provided under the underdrain units.Referring to FIG. 6, an end wall of the filter unit is provided with aplurality of perforations that provide mechanical engagement withgrouting material provided around the units.

U.S. Pat. No. 6,110,366 to Hunkele et al. discloses an anchor conceptfor securing an underdrain block to a filter floor. In particular,Hunkele discloses the use of anchors that comprise one or more wideningsextending outwardly from a rib so as to form ledges that are embedded ingrouting on a filter floor.

U.S. Pat. Nos. 3,110,667 to Stuppy and 4,619,765 to Roberts disclosefilter block constructions in which a bottom wall of the filter block isdefined with ridges or grooves.

SUMMARY OF THE INVENTION

In one embodiment, an underdrain filter block for use in draining andbackwashing a filtering media in a filter bed includes a top wall, apair of side walls extending from the top wall, and a bottom wallextending between the pair of side walls. The top wall, the pair of sidewalls, and the bottom wall define an upper portion and a lower portion.The lower portion includes a grout chamber having a plurality ofopenings defined by at least one of the bottom wall and the pair of sidewalls.

The grout chamber may be defined by a transverse wall extending from oneof the pair of side walls to the other of the pair of side walls. Theupper portion may include a primary chamber and at least one secondarychamber defined by a pair of angularly extending walls. The underdrainfilter block may further include a plurality of ribs generally extendingcircumferentially along the pair of side walls and the bottom wall. Thegrout chamber may extend the full length of the underdrain filter blockor may only extend a portion of the full length of the underdrain filterblock. The grout chamber may be recessed inwardly relative to anoutermost portion of the side walls. The upper portion may include aprimary chamber and at least one secondary chamber defined by an archedwall. The lower portion may include a plurality of grout chambersdefined by a grid-like structure positioned on a bottom surface of thebottom wall with the bottom wall defining a plurality of openings thatextend into each of the plurality of grout chambers, respectively. Theplurality of openings may be circular-shaped.

In another embodiment, an underdrain filter block for use in drainingand backwashing a filtering media in a filter bed includes a top wall, apair of side walls extending from the top wall, a bottom wall extendingbetween the pair of side walls, a plurality of ribs extendingcircumferentially along the pair of side walls and the bottom wall, anda plurality of wall segments extending between the plurality of ribs todefine a plurality of grout chambers. The plurality of grout chambersmay be positioned below the bottom wall. The plurality of wall segmentsmay each define a plurality of openings. The underdrain filter block mayfurther include a primary chamber and at least one second chamberdefined by an arched wall.

In a further embodiment, a method of installing an underdrain filterblock includes positioning an underdrain filter block adjacent to afilter floor. The underdrain filter block has a grout chamber at a lowerportion of the block and the block has a pair of side surfaces and abottom surface. The grout chamber includes a plurality of openingsdefined by at least one of the bottom surface and the pair of sidesurfaces of the block. The method further includes providing grout alongthe pair of side surfaces and the bottom surface such that grout extendsinto the plurality of openings.

The grout may be provided along the bottom surface of the block bypositioning a section of leveling grout on the filter floor. Theplurality of openings may be defined by the bottom surface and the pairof side surfaces of the block with the openings in the bottom surfaceand the pair of side surfaces each receiving grout. The underdrainfilter block may be positioned onto the section of leveling grout on thefilter floor. The grout may be provided along the pair of side surfacesof the underdrain filter block after positioning the underdrain filterblock onto the section of leveling grout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an underdrain filter block according to oneembodiment of the present invention;

FIG. 2 is a bottom view of the filter block of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of the filter block along theline 3-3 shown in FIG. 1;

FIG. 4 is a front view of the filter block of FIG. 1, showing the filterblock being laid on the base grout;

FIG. 5 is an enlarged cross-sectional view of a plurality of filterblocks shown in FIG. 1, showing the filter blocks installed;

FIG. 6 is a perspective view of an underdrain filter block according toa second embodiment of the present invention;

FIG. 7 is an enlarged cross-sectional view of the filter block along theline 7-7 shown in FIG. 6;

FIG. 8 is a perspective view of an underdrain filter block according toa third embodiment of the present invention;

FIG. 9 is a perspective view of an underdrain filter block according toa fourth embodiment of the present invention;

FIG. 10 is a perspective view of an underdrain filter block according toa fifth embodiment of the present invention; and

FIG. 11 is a perspective view of an underdrain filter block according toa sixth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of the description hereinafter, spatial orientation terms,if used, shall relate to the referenced embodiment as it is oriented inthe accompanying drawing figures or otherwise described in the followingdetailed description. However, it is to be understood that theembodiments described hereinafter may assume many alternative variationsand embodiments. It is also to be understood that the specific devicesillustrated in the accompanying drawing figures and described herein aresimply exemplary and should not be considered as limiting.

Referring to FIGS. 1-3, one embodiment of an underdrain filter block 10includes a top wall 15, a pair of side walls 17, and a bottom wall 19,which define a top surface 21, side surfaces 23, and a bottom surface25, respectively. The block 10 includes a plurality of reinforcing ribs27 on the exterior surface of the walls 15, 17, 19. The ribs 27 aregenerally oriented circumferentially around the block 10 rather thanalong a longitudinal axis of the block, although other rib orientationsand configurations may be utilized. The ribs 27 on the top wall 15 areseparate or discontinuous from the ribs positioned on the bottom wall19, although a single rib that extends circumferentially around theblock 10 may be utilized. As shown in FIG. 3, a transverse interior wall29 extends from one side wall 17 to the other side wall 17 to divide theinterior of block 10 into an upper portion 31 and a lower portion 33.The top wall 15 defines a recessed portion that extends along alongitudinal axis of the block 10. The side walls 17 are generallyplanar, although the side walls 17 may include recessed portions suchthat the width of the block 10 in cross-section is narrower in certainareas. The ends of the block 10 are configured to receive respectiveends of adjacent blocks so that a plurality of underdrain filter blocksmay be secured end-to-end.

The lower portion 33 of the block 10 includes a grout chamber 35 definedby the transverse wall 29, side walls 17, and bottom wall 19. The groutchamber 35 is open at each end of the block 10, although the chamber 35may be closed at one or both ends. The grout chamber 35 extendslongitudinally along the full length of the block 10, although thechamber 35 may have a length shorter than the full length of the block10. The upper portion 31 of the block 10 includes a primary chamber 37and a pair of secondary chambers 40, 41 defined by a pair of angularlyextending walls 43. Rather than providing the substantially planarangularly extending walls 43, the interior walls that define the primarychamber 37 and the secondary chambers 40, 41 may be arched or curvedsuch as those shown, for example, in FIGS. 6 and 7 discussed below. Thetop wall 15 and the angularly extending walls 43 define a plurality oforifices (not shown) to provide for the distribution of liquid and gasas known in conventional underdrain filter blocks.

The bottom wall 19 of the filter block 10 defines a plurality ofopenings 45 that extend into the grout chamber 35. Each of the sidewalls 17 also define a plurality of openings 47 in the lower portion 33of the block 10 with the openings 47 extending into the grout chamber35. The openings 47 in the side walls 17 are not provided for the fulllength of the block 10, but may be provided for the full length of theblock 10 in other configurations. Although the side walls 17 and bottomwall 19 include openings 45, 47, the side walls 17, or the bottom wall19, may alternatively not include openings. Further, the side walls 17and the bottom wall 19 may not be provided with openings that extendinto the grout chamber 35. In such an arrangement, the block 10 may beprovided with a grout introduction scoop (not shown) that is in fluidcommunication with the grout chamber 35. Furthermore, the openings 45,47 are substantially circular-shaped, but may have other configurationssuch as being oblong-shaped, square-shaped, or any other suitable shape.The grout chamber 35 may be formed integrally with the block 10 todefine a unitary, one-piece construction. The grout chamber 35 may alsobe formed from multiple pieces. In particular, the grout chamber 35 maybe formed separately and secured to the rest of the block 10 through afastening arrangement, such as by bolts or welding.

Referring to FIGS. 4 and 5, during the installation process, the block10 is secured in place by grout 50, 52 which flows into the groutchamber 35 through the openings 45, 47 in the side walls 17 and thebottom wall 19. The grout 50, 52 also flows around the grout chamber 35and the block 10 up toward the top of the side walls 17 of the block 10.

In one embodiment, the underdrain filter block 10 is installed asgenerally shown in FIGS. 4 and 5. In particular, as shown in FIG. 4, theblock 10 is positioned or set in leveling grout 50 provided on a filterfloor 54. The leveling grout 50 protrudes into the grout chamber 35slightly via the openings 45 in the bottom wall 19. Once the levelinggrout 50 has set up enough, the side grout 52 is applied. During theinstallation of the side grout 52, the grout chamber 35 on the lowerportion 33 of the block 10 is at least partially filled with grout. Asshown in FIG. 5, the entire grout chamber 35 may be filled with groutafter installation. The protrusion of the grout from the openings 45, 47in the grout chamber 35 holds the block 10 securely in place, therebyovercoming the buoyant forces acting on the block 10. Furthermore, theunderdrain filter block 10, particularly the bottom wall 19 of the block10, is stiffened by the grout 50, 52 that enters the grout chamber 35.The stiffening of the bottom wall 19 Sand the block 10 reducesdeflection or deformation of the block 10 due to the internal pressure.Thus, the grout chamber 35 and the openings 45, 47 prevent upliftfailure due to the internal pressure caused by headloss through theblock 10 and securely hold the filter block 10 on the filter floor 54.In a further embodiment, the filter block 10 is installed by securelyholding the block 10 with top and bottom supports (not shown) andinstalling grout between the bottom wall 19 of the block 10 and thefilter floor 54 and along the side walls 17 of the block 10 within ashort time frame.

Referring to FIGS. 6 and 7, an underdrain filter block 75 according to asecond embodiment is shown. The underdrain filter block 75 is similar tothe underdrain block 10 as shown in FIGS. 1-5 and discussed above. Likereference numerals are used for like parts. The underdrain block 75 ofthe present embodiment also includes a top wall 15, a pair of side walls17, and a bottom wall 19, which define a top surface 21, side surfaces23, and a bottom surface 25, respectively. The block includes aplurality of reinforcing ribs 27 on the exterior surface of the top wall15, side walls 17, and bottom wall 19. The ribs 27 generally extendcircumferentially around the block with the ribs 27 on the top wall 15being discontinuous as they extend from the top wall 15 to the side wall17. The ribs 27, however, extend continuously from the side walls 17 tothe bottom wall 19. A transverse wall 29 extends from one side wall 17to the other side wall 17 to divide the interior of block 75 into anupper portion 31 and a lower portion 33. The lower portion 33 of theblock 75 includes a grout chamber 35 defined by the transverse wall 29,side walls 17, and bottom wall 19. The grout chamber 35 only extends aportion of the full length of the block 75. Further, each of the sidewalls 17 are recessed inwardly where the transverse wall 29 begins.Thus, the grout chamber 35 is recessed compared to the outermost portionof the side walls 17.

Referring again to FIGS. 6 and 7, the upper portion 31 of the block 75includes a primary chamber 37 and a pair of secondary chambers 40, 41defined by an interior arched wall 77 extending from the transverse wall29 and connecting to the top wall 15. A gas conduit 79 is defined by thearched wall 77 and a second transverse wall 81. The top wall 15, archedwall 77, and second transverse wall 81 define a plurality of orifices(not shown) to provide for the distribution of liquid and gas. Thebottom wall 19 of the filter block 10 defines a plurality of openings 45that extend into the grout chamber 35. The side walls 17 also define aplurality of openings 47 in the lower portion 33 of the block 75 withthe openings 47 extending into the grout chamber 35. As shown in FIG. 6,the block 75 includes an end connector portion 83 that defines aplurality of openings 85. The openings 85 extend through the endconnector portion 83 in a direction that is parallel to a longitudinalaxis of the block 75. The end connector portion 83 may be utilized tosecure a plurality of blocks 75 end-to-end as discussed above inconnection with the block 10 shown in FIGS. 1-5. The block 75 may beinstalled in a similar manner as described above in connection with theblock 10 shown in FIGS. 1-5.

Referring to FIG. 8, an underdrain filter block 90 according to a thirdembodiment is shown. The underdrain filter block 90 is similar to theunderdrain block 10 as shown in FIGS. 1-5 and discussed above. Likereference numerals are used for like parts. The underdrain filter block90 includes a plurality of grout chambers 92 defined by wall segments 94positioned between ribs 96 that extend from a bottom surface of theblock 90. The wall segments 94 extend longitudinally between the ribs96. Thus, the grout chambers 92 are defined by the ribs 96 and the wallsegments 94. The wall segments 94 each define a plurality of openings 98for receiving grout as discussed above in connection with the openings45 of the underdrain filter block 10 shown in FIGS. 1-5. The interior101 of the block 90 may be similar to the upper portions 31 of theunderdrain filter blocks 10, 75 discussed above having angularlyextending walls or an arched wall to define primary and secondaryconduits. The block 90 may be installed in a similar manner as describedabove in connection with the block 10 shown in FIGS. 1-5 with the opensides of the grout chambers 92 receiving grout rather than the openings47 of the block 10.

Referring to FIG. 9, an underdrain filter block 110 according to afourth embodiment is shown. The underdrain filter block 110 is similarto the underdrain block 10 as shown in FIGS. 1-5 and discussed above.Like reference numerals are used for like parts. The underdrain filterblock 110 includes openings 45 in a bottom wall 19 and openings 47 ineach of the side walls 17 similarly to the underdrain filter block 10 ofFIGS. 1-5. The openings 47 of the underdrain filter block 110, however,are positioned at a location where the side walls 17 join the bottomwall 19 such that the openings 47 are non-circular. In particular, theopenings 47 of the underdrain filter block 110 have an upper circularportion with a generally-planar bottom portion. The block 110 may beinstalled in a similar manner as described above in connection with theblock 10 shown in FIGS. 1-5.

Referring to FIG. 10, an underdrain filter block 120 according to afifth embodiment is shown. The underdrain filter block 120 is similar tothe underdrain block 10 as shown in FIGS. 1-5 and discussed above. Likereference numerals are used for like parts. The underdrain filter block120 includes a grout chamber 35 that does not extend the full length ofthe block 120 thereby defining a cutout 122 adjacent to an end of theblock 120. The openings 47 in the side walls 17 of the underdrain filterblock 120 are similar to those described above in connection with theunderdrain filter block 110 shown in FIG. 9. The cutout 122 isconfigured to receive a support structure (not shown). For example, thecutout 122 may receive a uni-strut. The block 120 may be installed in asimilar manner as described above in connection with the block 10 shownin FIGS. 1-5.

Referring to FIG. 11, an underdrain filter block 130 according to asixth embodiment is shown. The underdrain filter block 130 is similar tothe underdrain block 10 as shown in FIGS. 1-5 and discussed above. Likereference numerals are used for like parts. The underdrain filter block130 includes a plurality of grout chambers 132 defined by a grid-likestructure 134 positioned on a bottom surface 136 of the underdrainfilter block 130. The bottom surface 136 of the block 130 defines aplurality of openings 138 that extend into each of the grout chambers132. The grid-like structure 134 strengthens the block 130 to limitdeflection or deformation of the bottom surface 136. Further, the groutchambers 132 each receive grout in a similar manner as described abovein connection with the grout chamber 35 of the underdrain filter block10 shown in FIGS. 1-5. The openings 138 allow air to evacuate to ensurethat the grout chambers 132 fill with grout, which further stiffens andstrengthens the block 130. The block 130 may be installed in a similarmanner as described above in connection with the block 10 shown in FIGS.1-5.

This invention has been described with reference to the preferredembodiments. Obvious modifications and alterations will occur to othersupon reading and understanding the preceding detailed description. It isintended that the invention be construed as including all suchmodifications and alterations.

The invention claimed is:
 1. An underdrain filter block comprising: atop wall; a pair of side walls extending from the top wall; a bottomwall extending between the pair of side walls; first and second ribs;and a wall segment extending between the first rib and the second rib todefine a grout chamber configured to receive grout during installationof the underdrain filter block.
 2. The underdrain filter block of claim1, wherein the first and second ribs extend along the pair of sidewalls.
 3. The underdrain filter block of claim 2, wherein the first andsecond ribs extend along the bottom wall.
 4. The underdrain filter blockof claim 1, wherein the first and second ribs extend along the bottomwall.
 5. The underdrain filter block of claim 1, further comprising aplurality of ribs and a plurality of wall segments each extendingbetween respective ribs of the plurality of ribs to define a pluralityof grout chambers.
 6. The underdrain filter block of claim 5, whereineach of the plurality of ribs extend along the pair of side walls. 7.The underdrain filter block of claim 6, wherein each of the plurality ofribs extend along the bottom wall.
 8. The underdrain filter block ofclaim 5, wherein each of the plurality of ribs extend along the bottomwall.
 9. The underdrain filter block of claim 1, wherein the wallsegment is positioned below the bottom wall.
 10. The underdrain filterblock of claim 1, wherein the wall segment defines a plurality ofopenings.
 11. The underdrain filter block of claim 12, wherein the topwall, the pair of side walls, and the bottom wall define a primarychamber and at least one secondary chamber.
 12. The underdrain filterblock of claim 1, wherein the bottom wall is imperforate.
 13. A methodof installing an underdrain filter block comprising: positioning anunderdrain filter block adjacent to a filter floor, the underdrainfilter block having a grout chamber at a lower portion of the block, theblock having a pair of side surfaces and a bottom surface, the groutchamber including a plurality of openings defined by at least one of thebottom surface and the pair of side surfaces of the block; providinggrout along the pair of side surfaces and the bottom surface such thatgrout extends into the plurality of openings.
 14. The method of claim13, wherein the grout is provided along the bottom surface of the blockby positioning a section of leveling grout on the filter floor.
 15. Themethod of claim 13, wherein the plurality of openings is defined by thebottom surface and the pair of side surfaces of the block, the openingsin the bottom surface, and the pair of side surfaces each receivinggrout.
 16. The method of claim 14, wherein the underdrain filter blockis positioned onto the section of leveling grout on the filter floor.17. The method of claim 16, wherein the grout is provided along the pairof side surfaces of the underdrain filter block after positioning theunderdrain filter block onto the section of leveling grout.
 18. Anunderdrain filter block comprising: a top wall; a pair of side wallsextending from the top wall; a bottom wall extending between the pair ofside walls, wherein the top wall, the pair of side walls, and the bottomwall define an upper portion and a lower portion, the lower portionincluding a plurality of grout chambers defined by a plurality of wallsegments forming a grid-like structure positioned on a bottom surface ofthe bottom wall.
 19. The underdrain filter block of claim 18, whereinthe bottom wall defines a plurality of openings that extend into each ofthe plurality of grout chambers, respectively
 20. The underdrain filterblock of claim 19, wherein each of the plurality of openings iscircular.